This invention pertains to a drawing frame for textile slivers and is more particularly directed to a device for pressing down the upper rolls onto the respective lower rolls of the drawing unit which is composed of serially arranged roll pairs formed of upper and lower rolls. The pressing device has a pressing arm which carries a force-generating device, such as a pneumatic cylinder provided with a back-and-forth movable member, such as a pressure rod for pressing the upper roll against the lower roll. Further, the upper rolls may be moved away from the lower rolls into an inoperative position.
During operation, the pressing arms are closed and the pressing devices press the upper rolls onto the associated lower rolls of the drawing unit. In case the drawing frame is at a standstill particularly for a longer time period, the pressing arms are opened to thus release the upper rolls from the pressing forces for protecting the roundness of the rolls and their elastic coating against deformation. In a known arrangement the pressing arms are pivoted open manually while the upper rolls remain stationarily positioned on the lower rolls. In case of operational disturbances, for example, if sliver is wound around the upper roll, the latter is manually lifted off its holding device against its weight and after removal of the wound loops it is preferably immediately repositioned. For inserting the slivers (in case of processing a different fiber type), for cleaning the drawing frame, for installing or removing or setting an axial pressure bar carried by the pressing arm or, in case of loop formation about a lower roll, all upper rolls have to be removed. The manual removal of particularly a plurality of upper rolls is time consuming and labor intensive. It is a further disadvantage of the prior art arrangement that particular space is required for depositing the upper rolls. It is also a drawback that the sensitive upper roll, particularly its coating, is likely to be damaged if handled carelessly.